This invention relates to an electronic timepiece including a system for compensating for the variation in a frequency of a time .[.reference.]. .Iadd.base .Iaddend.signal with a temperature by using a temperature signal generator. The electronic timepiece includes a time .[.reference.]. .Iadd.base .Iaddend.signal generator and means for forming a time .[.count.]. unit signal from the time .[.reference.]. .Iadd.base .Iaddend.signal. A .[.time counting mechanism.]. .Iadd.timekeeping means .Iaddend.is provided for keeping a time by using the time .[.count.]. unit signal and a time display .[.mechanism.]. .Iadd.device .Iaddend.is provided for displaying the time kept in the .[.time counting mechanism.]. .Iadd.timekeeping means.Iaddend..
The frequency of a time .[.reference.]. .Iadd.base .Iaddend.signal should essentially be kept in the restricted range even when the temperature of the surroundings of the timepiece is varied.
The specific resonance frequency must be changed with the external temperature even in a crystal oscillator which is used as a reference oscillator for a time .[.reference.]. .Iadd.base .Iaddend.signal generator used in high accuracy timepieces.
In order to overcome the problems of variations in the resonance frequency, the prior art includes several approaches. For example, with measurement equipment, a time .[.reference.]. .Iadd.base .Iaddend.signal generator is placed in a constant temperature vessel. With another approach, the frequency of an output is maintained by counter-balancing the thermal characteristics of the crystal oscillator to the temperature-capacity characteristic of a temperature sensing element thereby changing continuously the capacity of the time .[.reference.]. .Iadd.base .Iaddend.signal generator.
The first prior art approach has problems in that large amounts of electric power are consumed and a large space is required. Furthermore, with the second approach, it is difficult to find a temperature compensating element which has a temperature-capacity characteristic corresponding to that of the reference oscillator which is somewhat complex. In addition many types of temperature compensating elements do not have sufficient durability and stability and there are difficulties in forming an integrated circuit of the temperature compensating system.